The development of detection techniques for real-time detection of particles, such as air-borne or environmental contaminants, has been a major task of industries, such as the chemical industries, as well as national authorities attempting to control the evolution of borne contaminants. As a result of industrial processing of materials, fine particulates are generated which may be harmful to both humans and animals in the surrounding environment. With the increase in public demand for a cleaner and safer environment, the industries have been seeking low cost and handy devices that would be effective in providing real-time indication to the presence of such particulates, an indication which would initiate an immediate corrective and/or preventive response and/or further analysis and quantification.
Due to the usually low concentration of contaminants in the air, particularly at the on set of contamination, sampling devices, particularly those suitable for air sampling or for collection of residual contaminants from any one surface being in possible contact with the contaminants, have traditionally operated on the basis of sampling the environment for such particulates for later analysis, employing high sensitivity detection systems which are usually stationary, expensive and require skilled personnel for operation. Although numerous real-time detection methods of such particulate contaminants are known, they remain expensive and due to their complexity require the involvement of skilled operators.
It is therefore most desirable to have a device that is capable of providing almost instantaneous warning of the existence of contaminating particulates in the environment, e.g., in the air or on surfaces contained therein, at the lowest possible concentration, namely at the very onset of contamination, so that the individual may take steps to stop the contamination and/or avoid further exposure.